Basic support for Pico-W

[kripton]

This PR enables basic support for the Pico-W:

• It builds
• It uses the cyw43's LED but the LED blinking logic needs re-work anyways
• The code supports a WiFi AP + WiFi station
• It bumps up the CONFIG_VERSION to store the new WiFi data

Independent of that, it also drastically reduces the output size of the web app by purging unneeded CSS code and only importing the part of Bootstrap's JavaScript that will actually be used.

TODO:

• Runtime detection as in https://forums.raspberrypi.com/viewtopic.php?t=336775 (To have only ONE UF2-file for the Pico & Pico-W)
• Create an API for WiFi status and configuration
• Implement WiFi status and config in WebUI